It is known that a flat plate transmission line is made of an insulating plate placed between two metal plates. A current wave can be caused to propagate along the line by bringing the plates to different potentials and then generating an electric discharge between them.
When the potential difference between the metal plates is great, gas lasers of this type cease to function after a relatively short period of operation. Initially, erosion of the insulating material is observed on the edge of the transmission line, followed by peripheral breakdown between the metal plates.
Breakdown occurs even if care is taken to let the insulating plate extend beyond the metal plates.
The present invention aims to mitigate this disadvantage and to increase the reliability of gas lasers excited by means of a flat plate transmission line.